Eimeria tenella in chickens: development of resistance to quinolone anticoccidial drugs

Parasitology ◽  
1975 ◽  
Vol 71 (1) ◽  
pp. 41-49 ◽  
Author(s):  
H. D. Chapman
Keyword(s):  
Drug Resistance ◽  
Weight Gain ◽  
Liquid Nitrogen ◽  
Selection Pressure ◽  
Drug Tolerance ◽  
Eimeria Tenella ◽  
Cross Resistance ◽  
Drug Selection ◽  
Laboratory Conditions ◽  
Development Of Resistance

The development of drug resistance by the present Houghton strain of Eimeria tenella to the quinolones, methyl benzoquate and buquinolate, was found to take place after a single experimental passage. The development of resistance was independent of drug selection pressure and showed cross resistance to other quinolones, but not to amprolium and robenidine. When the Weybridge, Beltsville and Elberfeld strains of E. tenella were compared under similar laboratory conditions, the Weybridge and Elberfeld strains developed resistance to methyl benzoquate after 6 passages and the Beltsville after 5. Studies on the response of the Houghton strain to methyl benzoquate and buquinolate revealed that the drugs did not completely control the infection as measured by weight gain and that oocyst production was not suppressed. These observations indicate that the strain had already acquired some resistance to these drugs. This was confirmed by examining the resistance to methyl benzoquate of a culture of the Houghton strain of E. tenella which had been stored frozen in liquid nitrogen since 1969. This showed full sensitivity to the drug and developed resistance after 8 passages. This suggests that drug tolerance has been acquired by the Houghton strain since 1969.Oocyst lines were established from the Houghton strain by infecting single birds with approximately 10 oocysts. Eleven of these lines were found to be sensitive to methyl benzoquate, and nine to give rise to resistant parasites. It is concluded that the Houghton strain is contaminated by a small number of resistant oocysts which can be eliminated from a culture by dilution of the challenge inoculum. One of these Houghton oocyst lines, sensitive to methyl benzoquate, developed resistance after 8 serial passages.

Eimeria tenella: experimental studies on the development of resistance to robenidine

Parasitology ◽  
1976 ◽  
Vol 73 (3) ◽  
pp. 265-273 ◽  
Author(s):  
H. D. Chapman
Keyword(s):  
Drug Resistance ◽  
Selection Pressure ◽  
Experimental Studies ◽  
Eimeria Tenella ◽  
Parasite Population ◽  
Cross Resistance ◽  
Drug Selection ◽  
Development Of Resistance

The development of resistance by the Houghton strain (H) of E. tenella to robenidine has been studied, in the laboratory, by serially passaging the strain in chickens fed increasing concentrations of drug. Resistance to robenidine developed more readily in experiments using larger numbers of birds with higher numbers of oocysts in the inoculum. Both these factors increased the parasite population and increased the chance of selecting parasites resistant to the drug. E. tenella (H) was made resistant to 264 ppm robenidine and showed no cross-resistance to other anticoccidial agents. Resistance arose in a series of ‘steps’ as the concentration of drug was increased. E. tenella (H) was continuously passaged at concentrations ranging from 2 to 33 ppm of robenidine. After 16 passages, lines passaged at 2, 4 and 8 ppm were not resistant to 33 ppm robenidine, suggesting that the degree of resistance developed was dependent upon the drug selection pressure.

The development of resistance to metachloridine inPlasmodium gallinaceumin Chicks

Parasitology ◽  
1953 ◽  
Vol 42 (3-4) ◽  
pp. 277-286 ◽  
Author(s):  
Ann Bishop ◽  
Elspeth W. McConnachie
Keyword(s):  
Growth Rate ◽  
Drug Resistance ◽  
Normal Population ◽  
Rapid Development ◽  
Cross Resistance ◽  
Development Of Resistance ◽  
The Gift ◽  
Higher Doses ◽  
Resistance Tests ◽  
Selection Of

1. An increase in resistance to metachloridine of more than 100-fold was obtained within a few weeks in a strain ofPlasmodium gallinaceumtreated with gradually increasing doses of the drug and maintained in young chicks by blood-inoculation at intervals of 2–3 days.2. There was no evidence that the rapid development of resistance arose by the selection of highly resistant individuals present in the normal population.3. Two strains ofP. gallinaceumpassaged through chicks treated with 0·025 mg. doses of the drug gradually became resistant to greater concentrations than that to which they had been exposed, though their growth rate decreased when they were inoculated into birds receiving higher doses of the drug.4. In both strains maintained in birds treated with 0·025 mg. doses of the drug, resistance reached a maximum beyond which it did not increase.5. Cross-resistance tests failed to show any relationship in mode of action between meta-chloridine and pamaquin, mepacrine, quinine or chloroquine. A strain ofP. gallinaceum, highly resistant to metachloridine, showed slight resistance to sulphadiazine, sulphapyridine and sulphathiazole, but none to sulphanilamide or proguanil.We are indebted to the Cyanamid Products Ltd., London, for the gift of the Folvite used in these experiments.

Further studies on the use of chicken embryo infections for the study of drug resistance in Eimeria tenella

Parasitology ◽  
1976 ◽  
Vol 73 (3) ◽  
pp. 275-282 ◽  
Author(s):  
H. D. Chapman
Keyword(s):  
Drug Resistance ◽  
Drug Concentration ◽  
Chicken Embryo ◽  
The Other ◽  
Cross Resistance ◽  
Drug Resistant ◽  
Mutagenic Agent ◽  
Development Of Resistance ◽  
Drug Concentrations ◽  
Resistant Lines

Infections in the chicken embryo have been used to study the development of drug resistance in an embryo adapted strain of E. tenella. Resistance was developed to decoquinate, clopidol and robenidine by serially passaging this strain, but evidence for the development of resistance to amprolium was inconclusive. Resistance to decoquinate developed more readily than to the other drugs. Attempts to increase resistance to clopidol, robenidine and amprolium by increasing the sporozoite inoculum and by the use of a mutagenic agent were unsuccesful. No cross-resistance was found between the 4 drugs.Drug resistant lines of the Houghton strain (H) of E. tenella, made resistant to the 4 anticoccidial drugs by passage in chickens, were found to be resistant when evaluated using chicken embryo infections. Lines made resistant to decoquinate were not controlled by any concentration of this drug, suggesting that resistance, once developed, was absolute and not dependent on drug concentration. Lines made resistant to robenidine, clopidol and amprolium, however, were controlled by higher drug concentrations suggesting that in this case resistance was dependent on drug concentration.

scholarly journals A Strain of Bacillus sphaericus Causes Slower Development of Resistance in Culex quinquefasciatus

2002 ◽  
Vol 68 (6) ◽  
pp. 3003-3009 ◽  
Author(s):  
Guofeng Pei ◽  
Cláudia M. F. Oliveira ◽  
Zhiming Yuan ◽  
Christina Nielsen-LeRoux ◽  
Maria Helena Silva-Filha ◽  
...  
Keyword(s):  
Culex Quinquefasciatus ◽  
Selection Pressure ◽  
Bacillus Sphaericus ◽  
Continuous Selection ◽  
Cross Resistance ◽  
Binary Toxin ◽  
Promising Alternative ◽  
Low Level ◽  
Resistance Evolution ◽  
Development Of Resistance

ABSTRACT Two field-collected Culex quinquefasciatus colonies were subjected to selection pressure by three strains of Bacillus sphaericus, C3-41, 2362, and IAB59, under laboratory conditions. After 13 and 18 generations of exposure to high concentrations of C3-41 and IAB59, a field-collected low-level-resistant colony developed >144,000- and 46.3-fold resistance to strains C3-41 and IAB59, respectively. A field-collected susceptible colony was selected with 2362 and IAB59 for 46 and 12 generations and attained >162,000- and 5.7-fold resistance to the two agents, respectively. The pattern of resistance evolution in mosquitoes depended on continuous selection pressure, and the stronger the selection pressure, the more quickly resistance developed. The resistant colonies obtained after selection with B. sphaericus C3-41 and 2362 showed very high levels of cross-resistance to B. sphaericus 2362 and C3-41, respectively, but they displayed only low-level cross-resistance to IAB59. On the other hand, the IAB59-selected colonies had high cross-resistance to both strains C3-41 and 2362. Additionally, the slower evolution of resistance against strain IAB59 may be explained by the presence of another larvicidal factor. This is in agreement with the nontoxicity of the cloned and purified binary toxin (Bin1) of IAB59 for 2362-resistant larvae. We also verified that all the B. sphaericus-selected colonies showed no cross-resistance to Bacillus thuringiensis subsp. israelensis, suggesting that it would be a promising alternative in managing resistance to B. sphaericus in C. quinquefasciatus larvae.

The development of resistance to glycarbylamide and 2-chloro-4-nitrobenzamide in Eimeria tenella in chicks

Parasitology ◽  
1966 ◽  
Vol 56 (1) ◽  
pp. 25-37 ◽  
Author(s):  
S. J. Ball
Keyword(s):  
Drug Resistance ◽  
Resistant Strain ◽  
Parent Strain ◽  
Technical Assistance ◽  
Eimeria Tenella ◽  
Single Test ◽  
Normal Parent ◽  
Twofold Increase ◽  
Development Of Resistance ◽  
Resistant Strains

A twofold increase in resistance to glycarbylamide was induced in a strain of Eimeria tenella in chicks. This strain remained susceptible to amprolium, nicarbazin, nitrofurazone, zoalene, 3,5-dinitrobenzamide, 2-chloro-4-nitrobenzamide (M & B 5921) and spiramycin.At least an eightfold resistance to 2-chloro-4-nitrobenzamide (M & B 5921) was developed in another strain of E. tenella. This strain was also resistant to nitrofurazone, zoalene and 3,5-dinitrobenzamide, but not to glycarbylamide, amprolium, nicarbazin and spiramycin.A single test showed no transfer of drug-resistance when the two resistant strains were given simultaneously to the same birds.When a small number of parasites of a glycarbylamide-resistant strain of E. tenella was introduced into a larger inoculum of the normal parent strain, the resistant individuals appeared to diminish in number during passages through untreated chicks.I wish to thank Mrs B. M. Mitchell, Miss C. A. Hitchcock and Miss J. Watkins for technical assistance at various stages of the work.

Studies on insecticide resistance in cotton stainers, Dysdercus spp. (Hemiptera: Pyrrhocoridae), in Kenya

1982 ◽  
Vol 72 (3) ◽  
pp. 461-465 ◽  
Author(s):  
G. H. N. Nyamasyo ◽  
A. K. Karel
Keyword(s):  
Selection Pressure ◽  
Laboratory Strain ◽  
Cross Resistance ◽  
Poor Control ◽  
Eastern Province ◽  
Resistance Factors ◽  
Development Of Resistance ◽  
The Poor ◽  
Cotton Stainers ◽  
Selection For

AbstractResistance to carbaryl, lindane and methidathion was studied in field and laboratory strains of Dysdercus fasciatus Sign., D. nigrofasciatus Stål, D. superstitiosits (F.) and D. cardinalis Gerst. from Kenya. Four-day old fifth-instar female nymphs were found to be the most convenient for bioassay. The LC50s of carbaryl, lindane and methidathion for D. fasciatus were 372, 240, and 110 mg/litre, respectively, those for D. nigrofasciatus 337, 294, and 111 mg/litre, and that for carbaryl for D. cardinalis 147 mg/litre. The Meru and Ngwata strains of D. fasciatus had resistance factors of ×5·3 and ×6·1, respectively, to carbaryl. The field strains of all four species showed slight resistance (up to ×3·4) to lindane and methidathion. The poor control of Dysdercus spp. experienced in Eastern Province, Kenya, is probably due to the development of resistance to carbaryl. A laboratory and a field strain of each of D. fasciatus and D. nigrofasciatus were subjected to carbaryl selection pressure for six generations of doses equivalent to the LC50-LC70. The laboratory strain of D. fasciatus was also subjected to lindane selection for six generations. The laboratory and field strains of D. fasciatus developed resistance to carbaryl of ×3·7 and ×5·7, respectively, and cross-resistance to lindane of up to ×2·7. No significant increase in resistance was observed in D. nigrofasciatus after selection. The laboratory strain of D. fasciatus developed resistance to lindane of ×5·5 after selection and cross-resistance to carbaryl of ×4·3.

Impact of genotypic diversity on selection of subtype-specific drug resistance profiles during raltegravir-based therapy in individuals infected with B and BF recombinant HIV-1 strains

2020 ◽  
Vol 75 (6) ◽  
pp. 1567-1574
Author(s):  
Daniela Sánchez ◽  
Solange Arazi Caillaud ◽  
Ines Zapiola ◽  
Silvina Fernandez Giuliano ◽  
Rosa Bologna ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Current Knowledge ◽  
Phylogenetic Analyses ◽  
Genotypic Diversity ◽  
Resistance Testing ◽  
Cross Resistance ◽  
Resistance Mutations ◽  
Middle Income ◽  
Subtype B ◽  
Hiv 1

Abstract Background Current knowledge on HIV-1 resistance to integrase inhibitors (INIs) is based mostly on subtype B strains. This contrasts with the increasing use of INIs in low- and middle-income countries, where non-B subtypes predominate. Materials and methods HIV-1 drug resistance genotyping was performed in 30 HIV-1-infected individuals undergoing virological failure to raltegravir. Drug resistance mutations (DRMs) and HIV-1 subtype were characterized using Stanford HIVdb and phylogenetic analyses. Results Of the 30 integrase (IN) sequences, 14 were characterized as subtype F (47%), 8 as subtype B (27%), 7 as BF recombinants (23%) and 1 as a putative CRF05_DF (3%). In 25 cases (83%), protease and reverse transcriptase (PR-RT) sequences from the same individuals confirmed the presence of different BF recombinants. Stanford HIVdb genotyping was concordant with phylogenetic inference in 70% of IN and 60% of PR-RT sequences. INI DRMs differed between B and F IN subtypes, with Q148K/R/H, G140S and E138K/A being more prevalent in subtype B (63% versus 0%, P = 0.0021; 50% versus 0%, P = 0.0096; and 50% versus 0%, P = 0.0096, respectively). These differences were independent of the time on raltegravir therapy or viral load at the time of genotyping. INI DRMs in subtype F IN genomes predicted a lower level of resistance to raltegravir and no cross-resistance to second-generation INIs. Conclusions Alternative resistance pathways to raltegravir develop in subtypes B and F IN genomes, with implications for clinical practice. Evaluating the role of HIV-1 subtype in development and persistence of mutations that confer resistance to INIs will be important to improve algorithms for resistance testing and optimize the use of INIs.

Emergence of ceftazidime/avibactam resistance in KPC-3-producing Klebsiella pneumoniae in vivo

2019 ◽  
Vol 74 (11) ◽  
pp. 3211-3216 ◽  
Author(s):  
Stephan Göttig ◽  
Denia Frank ◽  
Eleonora Mungo ◽  
Anika Nolte ◽  
Michael Hogardt ◽  
...  
Keyword(s):  
Combination Therapy ◽  
Klebsiella Pneumoniae ◽  
Selection Pressure ◽  
Galleria Mellonella ◽  
Phenotypic Characterization ◽  
Infection Model ◽  
Development Of Resistance ◽  
Time Kill

Abstract Objectives The β-lactam/β-lactamase inhibitor combination ceftazidime/avibactam is active against KPC-producing Enterobacterales. Herein, we present molecular and phenotypic characterization of ceftazidime/avibactam resistance in KPC-3-producing Klebsiella pneumoniae that emerged in vivo and in vitro. Methods Sequence analysis of blaKPC-3 was performed from clinical and in vitro-generated ceftazidime/avibactam-resistant K. pneumoniae isolates. Time–kill kinetics and the Galleria mellonella infection model were applied to evaluate the activity of ceftazidime/avibactam and imipenem alone and in combination. Results The ceftazidime/avibactam-resistant clinical K. pneumoniae isolate revealed the amino acid change D179Y in KPC-3. Sixteen novel mutational changes in KPC-3 among in vitro-selected ceftazidime/avibactam-resistant isolates were described. Time–kill kinetics showed the emergence of a resistant subpopulation under selection pressure with either imipenem or ceftazidime/avibactam. However, combined selection pressure with imipenem plus ceftazidime/avibactam prevented the development of resistance and resulted in bactericidal activity. Concordantly, the G. mellonella infection model revealed that monotherapy with ceftazidime/avibactam is prone to select for resistance in vivo and that combination therapy with imipenem results in significantly better survival. Conclusions Ceftazidime/avibactam is a valuable antibiotic against MDR and carbapenem-resistant Enterobacterales. Based on time–kill kinetics as well as an in vivo infection model we postulate a combination therapy of ceftazidime/avibactam and imipenem as a strategy to prevent the development of ceftazidime/avibactam resistance in KPC-producing Enterobacterales in vivo.

Stability of spinosad resistance inFrankliniella occidentalis(Pergande) under laboratory conditions

2008 ◽  
Vol 98 (4) ◽  
pp. 355-359 ◽  
Author(s):  
P. Bielza ◽  
V. Quinto ◽  
C. Grávalos ◽  
E. Fernández ◽  
J. Abellán ◽  
...  
Keyword(s):  
Resistant Strain ◽  
Selection Pressure ◽  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Laboratory Conditions ◽  
Flower Thrips ◽  
Factors Influencing ◽  
Stability Of Resistance ◽  
The Stability ◽  
Successive Generations

AbstractThe stability of spinosad resistance in western flower thrips (WFT),Frankliniella occidentalis(Pergande), populations with differing initial frequencies of resistance was studied in laboratory conditions. The stability of resistance was assessed in bimonthly residual bioassays in five populations with initial frequencies of 100, 75, 50, 25 and 0% of resistant individuals. There were no consistent changes in susceptibility of the susceptible strain after eight months without insecticide pressure. In the resistant strain, very highly resistant to spinosad (RF50>23,000-fold), resistance was maintained up to eight months without further exposure to spinosad. In the absence of any immigration of susceptible genes into the population, resistance was stable. In the case of the population with different initial frequency of resistant thrips, spinosad resistance declined significantly two months later in the absence of selection pressure. With successive generations, these strains did not change significantly in sensitivity. Spinosad resistance inF. occidentalisdeclined significantly in the absence of selection pressure and the presence of susceptible WFT. These results suggest that spinosad resistance probably is unstable under field conditions, primarily due to the immigration of susceptible WFT. Factors influencing stability or reversion of spinosad resistance are discussed.

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